Nine protesters have been arrested for civil disorder in demonstrations against a right-wing ball in Vienna's imperial Hofburg Palace, Austrian police said on Saturday.

More than 2,500 joined protests against the Academics' Ball on Friday night which was hosted by Austria's far-right Freedom Party and has in the past attracted right-wing icons such as France's Marine le Pen.

Police had closed off a large area around the palace, which contains several museums and the office of the Austrian president, ahead of the protests by mainly green and left-wing student groups, after clashes at the event last year.

Two of the 780 ball-goers were slightly hurt, on Saturday.

Heinz-Christian Strache, leader of the Freedom Party, caused outrage last year when he said right-wing sympathizers who had been intimidated by protesters as they arrived at the ball could be considered the "new Jews".

The ball, one of hundreds that take place in Vienna every January and February, has split Viennese society, with some arguing that anyone should be allowed to organize such an event, while others say it legitimizes extreme right-wing views.

Austria, which was annexed by Nazi Germany in 1938, has laws that ban Nazi symbolism and prevent the establishment of neo-Nazi parties.

Strache recently announced that he would not attend this year's Academics' Ball, saying he planned to be on holiday.